For the last decade of his life, Ronald Reagan was an icon in absentia. The former president had made no formal public appearances since his poignant 1994 letter announcing his Alzheimer's disease. Even contact with old friends was carefully rationed. It was Nancy Reagan's final, fierce effort to protect her husband's image.

Former president Ronald Reagan addresses the guests at the dedication ceremony for his presidential library in Simi Valley, Calif. on Nov. 4, 1991.

By Marcy Nighswander, AP

"We wanted the picture of him the way we knew him, and not in the throes of Alzheimer's," says Sheila Tate, who served as the first lady's press secretary in the 1980s.

Partly for that reason, Reagan had remarkable staying power. Long after he dropped from public view, he remained a hero of conservative causes and a symbol of an optimistic era. One sign of the size of the shadow he cast: the first piece of legislation that President Bush signed into law was a resolution honoring Reagan's 90th birthday.

When Reagan left the White House in January 1989, he hoped to enjoy a vigorous retirement on his ranch in California's Santa Ynez mountains, punctuated by public appearances for favorite causes. But within a few years, relatives and former staffers were noticing signs of failing mental abilities.

Famously adept at handling prepared speeches, Reagan was off balance at a January 1993 dinner honoring him in Washington. Several months later, a battery of tests at the Mayo Clinic revealed evidence of deterioration in his memory. Reagan continued to make public appearances, but aides worried about his ability to perform when he took the podium. In the fall of 1994, while taping campaign advertisements for Republican candidates, the veteran trouper had difficulty reading from a teleprompter. In November, his Los Angeles office released Reagan's handwritten letter announcing his diagnosis.

Reagan's further deterioration appears to have happened fast. He did not attend a 1996 celebration his wife held to celebrate his 85th birthday at Chasen's, the Los Angeles watering hole where Reagan proposed to her. Friends who did attend reported being told that Reagan no longer recognized some people he had known for years.

But Reagan did not become a recluse. For the next five years, he continued to make regular appearances at his office on Avenue of the Stars in Century City. Devoted staff members helped him manage correspondence and prompted him with the names of his visitors. That sometimes included reminding Reagan of how he knew them.

Despite his mental frailty, Reagan remained physically fit. He continued to take constitutionals in parks near his Los Angeles home, genially stopping to pose for pictures with tourists who recognized him. His deliberately unchanging routine — an important element in managing Alzheimer's — included a weekly game of golf at the Los Angeles Country Club. The late comedian Bob Hope was one of his golf partners.

When Reagan broke his hip in a fall at his home in 2001, he received more than 10,000 get-well wishes from admirers worldwide. After that, he was virtually housebound.

his body was taken to a Santa Monica funeral home Saturday, it was with the full dignity of the high office he once held: The hearse was surrounded by Secret Service agents.

"They walked along, touching the car," Tate says, "just like when he was president."